I can only recall two other authors whose work ever caused me to laugh out loud, P.G. Wodehouse, whose inimitable tales of the ineffably dense but lovable Bertie Wooster and his man Jeeves fill several howling volumes, and Carl Hiaasen, whom I'd never heard of when I checked one of his novels out of the USIA "library" in Vilnius, Lithuania, and who prompted a gaspy laugh when one of his characters quite suddenly shot someone in the foot. (I'm still a Hiaasen fan, but know what to expect now, so don't laugh out loud anymore.)
If you don't know much about Bryson, he's an American expatriate who first scored success in the UK, where he lives, and where he is a big deal, though nowadays he has a considerable following in the U.S., too. As far as I know, he writes exclusively nonfiction which is a shame, because I'd love to read a Bryson novel.
Who's the funniest author you've ever read? Did you have to wipe away tears before you could turn the page?